Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.
Codeship - Codeship is a fast and secure hosted Continuous Delivery platform that scales with your needs.
Buddy - The simplest CI/CD tool ever made, acclaimed by top developers worldwide. It uses delivery pipelines to build, test and deploy software. Pipelines are created with over 100 ready-to-use actions, that can be arranged in any way.
TeamCity - TeamCity is an ultimate Continuous Integration tool for professionals